The health risks Sophie faced

The Countess's ectopic pregnancy two years ago meant doctors were well aware of the increased risk of complications during labour and delivery.

However, an emergency Caesarean section is usually performed because of potentially life-threatening complications to the mother and her baby.

Even so, women who are technically infertile - taken more than a year to conceive - have a much higher likelihood of having an emergency Caesarean, premature delivery and a low birth weight child, according to recent research.

Late in pregnancy, a major cause of an unplanned Caesarean is the appearance of symptoms suggesting the mother is developing preeclampsia.

These include rising blood pressure, swollen ankles and legs and bleeding.

Without prompt action, the condition may result in the deaths of the woman and her child.

Another complication is the development of diabetes during pregnancy which needs monitoring and can result in an emergency Caesarean.

Labour may have started prematurely at 36 weeks - a month before the baby was due.

Babies born at 37 weeks and earlier are classified as premature and many pre-term babies are transferred to a hospital neo-natal unit for surveillance.

A shortage of NHS neo-natal facilities means it is relatively common for babies to be separated from their mothers.

The move to St George's could be a precaution, or suggest extra facilities and expertise available at a teaching hospital might be needed.